Pictrs instability

Been getting a lot of instability out of pictrs the last two days. Nothing in the week before that.

By instability, I'm talking 500 errors when uploading images (POST https://lemm.ee/pictrs/image). They seem pretty much random, I can get around the errors by just repeatedly trying to upload the same file until it works. As far as I can tell, there's nothing I'm doing wrong, trying to upload images too large produces a different, and much more reasonable, error. And there's no info at all in the response, except for the 500 code itself.